This invention relates to improvements in a vibration reducing system for reducing vibration of an internal combustion engine itself, caused by fluctuation of combustion pressure in the engine, and more particularly to the vibration reducing system for reducing roll vibration of the engine itself by using an inertial mass member which rotates in a right or reverse direction relative to a crankshaft.
Recently, attention has been increasingly paid on improving fuel economy in automotive engines, from the viewpoint of environmental protection, and therefore footlights have been put on direct injection gasoline-fueled engines and direct injection diesel engine in which fuel is directly injected into each engine cylinder, for automotive vehicles. However, such engines are high in combustion exciting force and accordingly large in roll vibration due to torque fluctuation as compared with conventional engines. Thus, such engines will induce booming noise within a passenger compartment, due to the roll vibration of the engine, and increase or degrade floor vibration of a vehicle body.
In view of the above, as a measure for solving the above drawbacks, a vibration reducing system for an internal combustion engine has been proposed in Japanese Patent Provisional Publication No. 6-33990.